The sisters, ages 12, 13, and 17, told police they were held in captivity and filth by their mother and stepfather. The two younger girls escaped early Tuesday and fled to a neighbor's house, after their stepfather allegedly threatened them with a knife, the paper said.

Tucson Police Department spokesman Sgt. Chris Widmer told the paper that the girls' 34-year-old stepfather, and their mother, 32, were in a local jail on Tuesday. They are facing three counts of kidnapping, emotional child abuse, and physical child abuse. The stepfather also faces one count of sexual abuse with a person under 15 years old.

The case is being investigated as alleged child abuse and imprisonment. Tucson Police Capt. Michael Gillooly said at a news conference that the girls were malnourished and dirty, and told authorities they hadn't bathed in up to six months.

"They were kept in filthy living conditions," Gillooly said, adding that the two youngest girls were kept in a separate bedroom from their 17-year-old sister.

Police were called to a neighboring home Tuesday and found the two younger girls, who said they were in a bedroom in the house when their stepfather kicked the door in and threatened them with a knife. The girls said they were able to escape and reach the residence of the neighbor, who called 911. Police then found the oldest sister locked in a bedroom of the home, where she said she hadn't been allowed to see her siblings for two years, the Star reported.

Widmer told reporters that the girls reported being fed "once a day."

The paper reported that police removed plastic bags with evidence and what appeared to be a computer tower.